Robotic systems having one or more user controlled robotic arms are used in many applications. As one example, see U.S. Pat. No. 7,865,266 B2, entitled “Cooperative Minimally Invasive Telesurgical System,” which is incorporated herein by reference. Additional examples may be found in manufacturing, construction, hazardous material handling, and other applications such as those using teleoperation.
Failures or faults may occur in the robotic arms during their operation that result in loss of full control. To avoid such loss, fault tolerant systems may be employed such as those providing triple redundancy so that a fault may be readily determined and if one component fails, a surviving component may still provide the function. Providing redundant components, however, adds to system cost. Alternatively, preventive maintenance techniques may be employed to minimize the occurrences of such faults. However, unexpected faults may still occur.
When a fault or failure is detected in a robotic system, the entire system may be turned off for safety reasons until the fault can be corrected. Sometimes, however, the robotic system may still be usable to accomplish a primary or secondary task in a degraded state. In this case, it may be advantageous to allow the system to continue operating in the degraded state. Other times, the fault may not be persistent. In this case, clearing the fault and continuing full use of the robotic system may be possible.